I found a road out in the country where I grew up that was straight as far as you could see and no intersections within a mile. I then selected one laser and put a manual shooting point straight down the road to the west. Then select the second laser so both are selected/blue and put a manual shooting point to the east straight down the road. You need to always have both guns selected for them to continue to shoot in your location.

Remember to set your phone to as long as it will go before the screen shuts down and the game will play itself...you need to interact once about every 2 minutes because it will tell you "All Missions Done" or something similar.

There are a lot of roads like this in North Dakota and other Prairie States, but I found mine in Michigan's Thumb.

This process will also give you GREAT progress against the following also: